Generally, a fuel cell-powered vehicle or a fuel cell-hybrid vehicle, which has a fuel cell and a battery, starts with a supply of air using a high-voltage air blower. Here, the high-voltage air blower is driven with high voltage supplied from a high-voltage battery which outputs the high voltage boosted via a DC-DC converter. However, if the high-voltage battery or the DC-DC converter breaks down, it is impossible to start the fuel cell-powered vehicle or fuel cell-hybrid vehicle.
A fuel cell stack has a structure in which hundreds of sheets of cells, each consisting of a hydrogen-reactive layer as an anode and an oxygen-reactive layer as a cathode as are stacked on each other. When a power system stops operating, a supply of air stops so as to lower a voltage output from the fuel cell, and an electric current is consumed via the connection of a resistor or the charge of the battery using the DC-DC converter, thereby exhausting remaining oxygen in the cathode. Here, the cathode maintains a nitrogenous atmosphere.
However, as time elapses after the system stops operating, air is externally introduced into the cathode, gradually forming an oxygen-rich atmosphere. In this state, if the air blower fails to operate due to the breakdown of the DC-DC converter or the battery, the system of the fuel cell-powered vehicle cannot start. Thus, the fuel cell-powered vehicle has to be repaired.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.